Combination lock

ABSTRACT

A combination lock comprises a plurality of manually rotatable rings coaxially mounted about a rotatable member, a protruding cam end of a bowed annular spring fixed in an annular groove in the member pressing outwardly against inner cylindrical surfaces of the rings. Reference marks on the rings and on a non-manually rotatable external part of the member can be set to a combination corresponding to alignment of grooves in the inner surfaces of the rings with the cam, in which case the cam engages in the grooves and locks one of the rings for rotation with the member. The other grooves each have a profile such that their ring does not lock for rotation with the member, so that rotation of these rings causes retraction of the cam from the grooves.

- United States Patent [191 Plq [4 Apr. 9, 1974 COMBINATION LOCK Primary Examiner-Joseph H. McGlynn [76] Inventor: Bernard Piq, Chantebrise-Le Grand Asslstam Exammer k chard Tremblay Champ, 69 SouciewenJarrest, Attorney, Agent, or Firm-Robert E. Burns; Emman- France uel J. Lobato [22] Filed: May 19, 1972 [21] Appl. No.: 254,914 [57] ABSTRACT A combination lock comprises a plurality of manually rotatable rin s coaxial] mounted about a rotatable [3O] Forelgn 9 Pnomy Data member, a p rotruding Zam end of a bowed annular May 19, 1971 Switzerland 7348/71 Spring fixed in an annular groove in the member press ing outwardly against inner cylindrical surfaces of the [52] US. Cl 70/165, 70/231, 70/318 rings Reference marks on the rings and on a new [511 f 365d 55/14 Eosb 37/02 Fl6b 41/00 manually rotatable external part of the member can be [58] Fleld 0f Search 70/167, 171, 213, 312, Set to acombination Corresponding to alignment of 70/315 318 grooves in the inner surfaces of the rings with the cam, in which case the cam engages in the grooves and [56] References cued locks one of the rings for rotation with the member. UNITED STATES PATENTS The other grooves each have a profile such that their 3,521,471 7/1970 Aretola 70/213 x g does not lockrfor rotation with the member, 80 1,898,947 2/1933 Frey l. 70/312 that rotation of these rings causes retraction of the 972,171 8/1910 Dupont 70/21 cam from the grooves, 2,355,888 8/1944 Nusbaum 70/171 X 4 Claims, 9 Drawing Figures 15 j 3'- r 12 i COMBINATION LOCK The invention relates to combination locks.

According to the invention, there is provided a combination lock including at least two manually rotatable coaxial actuating rings each carrying a series of external reference marks, the actuating rings being placed about a rotatable member including a non-manually rotatable external surface carrying at least one reference mark, the actuating rings having coaxial cylindrical inner walls each provided with a recess, and an intermediary driving piece fixed for rotation with the rotatable member, an elastically radially outwardly urged active part of the driving piece being adapted to bear against said cylindrical inner walls when at least one of the recesses is out of alignment with the active part and to engage in the recesses to lock the rotatable member for rotation with at least one of the actuating rings when the rings are placed with a combination of their reference marks corresponding to alignment of all of .the recesses with the active part, in which the driving piece is formed by a bowed spring constrained to the form of a split ring andlodged in an annular groove defined between a peripheral wall of the rotatable member and the cylindrical inner walls of the actuating rings, a portion of the spring being fixed to the rotatable member, and a free end of the spring having an outwardly protruding cam forming said active part, a first one of said recesses having a profile which is adapted when the actuating rings are placed with said combination to engage with the cam and lock the corresponding first actuating ring for rotation with the rotatable member, and a second one of the recesses having a profile which is adapted when the actuating rings are placed with said combination to move the cam out of engagement with the recesses when the corresponding second actuating ring is turned.

A lock according to the invention may conveniently be incorporated in a fuel tank cap, for example for an automobile vehicle. Alternatively, it could be used in a door lock, in which case the actuating rings would form part of a handle, and the rotary member would be integral with a door-catch actuating shaft.

An embodiment of the invention will now be particularly described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is an elevational view, partly in axial crosssection, of a fuel tank cap incorporating a lock according to the invention;

FIG. 2 is a cross-section taken along linen-11 of FIG. 1;

FIG. 3 is a cross-section taken along line III-III of FIG. 1;

FIG. 4 is a plan view of the cap shown in FIG. 1;

FIG. 5 is a plan view of the intermediary driving member, in the form of an open spring, in its unstressed condition;

FIG. 6 is an elevational view of the spring shown in FIG. 5;

FIG. 7 and 8 are elevational views of the actuating rings of the lock; and

FIG. 9 is a schematic plan view showing the cap of FIG. 1 in a locked" position.

Referring to FIG. 1, the combined combination lock and cap 1 for a fuel tank of an automobile comprises a tubular rod 2 open at its threaded lower end 4 and closed at its upper end with a flange-like disc 3. About the rod 2 are placed two sleeve-like parts Sand 6, axially held by means'of a nut 28 screwed onto end 4, the upper part 6 having a central counterbore receiving the disc 3. The lower end of part 5 has an extemal'screw thread 27, or other means enabling the cap 1 to be secured in or removed from a cooperating recess (not shown) at an end of a conduit leading to a fuel tank, by a rotary motion of the member formed by parts 5 and 6.

Parts 5 and 6 each have, in axial cross-section as shown in FIG. 1, facing housings 5a and 6a each of substantially L-shape, together forming a substantially T- shaped annular housing, the central stem of the T- being directed radially outwards and therefore opening at the periphery of member 5/6. Two actuating rings 7 and-8,

each of substantially U-shaped cross-section with the inner arms 9 and 10 of the Us shorter than the outer arms, are axially superimposed so as to form an overall substantially H-shaped section, and are lodged with the arms 9 and 10 engaging in the T-shaped annular housing of member 5/6. The outer cylindrical surface of the member 5/6 is thus rendered inaccessible from outside the cap 1 and, since the only accessible outer part of the surface of member 5/6 is substantially flat and smooth, the member 5/6 therefore cannot be manually turned from outside the cap 1. Member 5/6 can thus mediary driving member in the form of a spring 20 provided with an outwardly protruding cam 21 and lodged in an annular groove 11 in the part 6, the lower wall of this groove 11 being formed by the upper face of part 5.

As shown in FIGS. 5 and 6, the spring 20, which may be in metal or a synthetic plastics material, when in its unstressed state has approximately the shape of a horseshoe whose arm opposite that of cam 21 is cut away. As shown in FIGS. 2 and 3, when the spring is bowed in groove 1 1, it takes the form of a split annulus or ring. With the exception of its end carrying the cam 21, the spring 20 is connected to parts 5 and 6' by means of five equally spaced-apart pins 22 (FIG. 6) protruding from opposite faces thereof, these pins 22 engaging in five of six corresponding equally spaced apart axial blind bores in each of the facing annular walls of parts 5 and 6 which axially define the groove 11. One of these bores in part 6, i.e. the one in which no pin 22 is engaged, is schematically indicated by reference numeral 24 in FIG. 2.

The outer face of groove 11 is limited by the neighboring zones of the cylindrical inner walls of rings 7 and 8.

The inner cylindrical wall of ring 8 is provided with a recess 26 (FIG. 2) having substantially the same rectangular cross-sectional shape as the cam 21, and adapted when it receives the cam 21 to lock the ring 8 and the member 516 for rotation together. The inner cylindrical wall of the other ring 7 is provided with a recess 25 (FIG. 3) also adapted to receive cam 21. However, the recess 25 .has inclined lateral walls profiled such that if the ring 7 is turned whilst the cam 21 is engaged in the recesses 25 and 26, the cam is moved by these lateral walls out of engagement with the recesses, and comes to bear against the inner cylindrical surface of the ring 7. In other words, the ring 7 is not locked.

for rotation with the member /6.

As is apparent from FIGS. 1 to 3, the cam 21 can only engage in the recesses 25 and 26 when these two recesses are in alignment with one another and with the cam 21. If, as shown in FIG. 9 for example, the recesses 25 and 26 are not so aligned, the outer face of the cam 21 bears against the inner cylindrical walls of the rings 7 and 8 and, when the rings are turned, the cam 21 slides over these surfacesln this position, the ring 8 is therefo e not locked for rotation with the member 5/6.

In order to enable the user to locate the position of FIGS. 1 to 3 in which the cam 21 engages in the recesses 25 and 26, three series of reference marks are provided. The first series of marks 29 (FIG. 4-) is carried bythe non-manually rotatable external surface of the member 6, i.e. on the upper part of the cap I, and is composed, for example, of the signs Roman I to VI equally spaced in an annular arrangement. The other series of reference marks 30 and 31 (FIGS. 7 and 8) are engraved on the cylindrical outersurfaces of two rings 12 and 13. These graduated rings 12 and 13 are fitted in peripheral annular grooves in the actuating rings 7 and 8. Rings 14 and 15 each carry six pins 16, 17 respectively protruding from one face thereof in an axial direction, adapted to be received in six corresponding axially directed blind bores 18 and 19 (FIGS. 2 and 3) in the rings 7 and 8. Graduated ring 12 is thus fixed for rotation with the actuating ring 7, and likewise for rings 13 and 8. The reference marks 30 and 31 are formed by the numbers 1m 6 and 1 to 6' equally spaced about the peripheries of the rings 14 and 15, these numbers being schematically indicated, enclosed within circles, in FIGS. 1, 7, 8 and 9 for the purpose of explanation. It can be seen that in the example given, the correct combination which enables the cap 1 to be screwed onto or unscrewed from its cooperating recess is formed by an alignment of the marks I, 1 and 1', and a liaison enabling the ring 8 to be locked for rotation with the member 5/6 can only be obtained if this combination is shown.

Operation of the described combination lock and cap assembly is simple. In the position of the cap shown in FIG. 1, with the correct combination displayed, the cap 1 is placed in its cooperating recess at an end of a con duit leading to the fuel tank and is screwed in by turning the actuating ring 8. The ring 7 isthen turned, which radially inwardly moves the cam 21 out of the recesses 25, 26 by the action of the inclined lateral walls of recess 25. The ring 8 is then turned so that the 22 respectively engage. The operational one of reference marks 29 can thus be changed by angularly displacing the spring 20in relation to the part 6. Similarly, the operational one of reference marks 30 and 31 can be changed by angularly displacing the graduated rings 12 and 13 in relation to their respective actuating rings 7 and 8.

Various modifications may bemade to the described embodiment without departing from the scope of the appended claims. For example, the rotatable member could be made in a single piece instead of two parts as described in order to simplify the construction. It would also be possible to dispense with the separate graduated rings, and reference marks could be engrayed directly on the actuating rings. It is also possible to use more than two coaxial actuating rings each bearing a series of external reference marks and a recess in an inner cylindrical surface, thereby increasing the number of possible combinations of reference marks and consequently decreasing the chance of finding the correct combination by hazard. In such a case, preferably only one of the recesses would have the shape of recess 26 (FIG. 2) and thereby be adapted to be locked for rotation with the rotatable member. All of the other recesses would have the shape of recess 25 (FIG. 3), so that a person unaware of the correct combination would not only be obliged to set the correct combination, but once the combination was set would have to know which ring should be turned to screw or unscrew the cap.

Another possibility of increasing the number of available combinations is to increase the number of reference marks, e.g. from O to 9 instead of from I to 6, and provide a corresponding number of cooperating pins and bores in the various components. The number of reference marks could also be a whole number multiple of the number of cooperating pins and bores.-

A lock according to the invention can also be incorporated into a door handle unit. In this case, the actuating rings form part of a door knob, and the rotatable member is integral with a latch actuating shaft, generreference mark 1 is no longer in face with mark I, i.e.

so that the recess 26 is no longer facing the cam 21.

Such a random position of the rings is illustrated in FIG. 9 and, in this position, a person who is unaware of the correct combination cannot unscrew the cap 1, since it is extremely unlikely that the correct combination could be found by hazard.

The described combination lock also has the feature of permitting changing of the operative combination whenever desired by the user. For this purpose, the parts composing the cap 1 are dismantled axially by removing the lock nut 28, which is only accessible when the cap 1 is removed from its cooperating recess. The combination can be changed by re-assembling the cap 1 with its component parts disposed with a different relative angular disposition to one another, by changing the bores 18, 19 and 24 in which the pins 16, 17 and ally of square cross-section. To change the combination, the knob and/or the latch mechanism could be made removable in a known manner.

A lock according to the invention could also be put to other uses, for example as an adjusting or control knob for a mechanical or other installation, whenever it is desired that only authorized persons should be able to manipulate the knob.

What is claimed is:

1. Combination lock including a rotatable member including a non-manually rotatable surface carrying at least one reference mark, at least two manually rotatable coaxial actuating rings each carrying a series of external reference marks, the actuating rings being placed about said rotatable member, the actuating rings having coaxial cylindrical inner walls each provided with a recess, an intermediary driving piece fixed for rotation with the rotatable member, an elastically radially outwardly urged active part of the driving piece bearing against said cylindrical inner walls when at least one of the recesses is out of alignment with the active part and engageable in the recesses to lock the rotatable member for rotation with at least one of the actuating rings when the rings are placed with a combination of their reference marks corresponding to alignment of all of the recesses with the active part, said driving piece comprising a bowed spring constrainedto I the form of a split ring, said rotatable member and actuating rings defining an annular groove defined between a peripheral wall of the rotatable member and the cylindrical inner walls of the actuating rings, said spring being disposed in said annular groove, a portion of the spring being fixed to the rotatable member, and a free end of the spring having an outwardly protruding cam forming said active part, a first one of said recesses having a profile which is adapted when the actuating rings are placed in said combination to engage with the cam and lock the corresponding first actuating ring for rotation with the rotatable member, a second one of the recesses having a profile which is adapted when the actuating rings are placed in said combination to move the cam out of engagement with the recesses when the corresponding second actuating ring is turned, and

means for fixing said portion of the spring to the rotat-.

able member in any one of a plurality of discrete positions each corresponding to a reference mark on the external surface of the rotatable member.

2. Combination lock according to claim 1, in which the rotatable member comprises two sleeve-like parts gageable in selected ones of the bores to hold the two sleeve-like parts in a given angular relation to one another and to the spring.

3. Combination lock according to claim 1 in which said actuating rings comprise two axially superimposed actuating rings, said actuating rings each having a substantially U-shaped section which when the rings are placed together form a substantially H-shaped section, the inner arms of the U-sections being shorter than the outer arms, said rotatable member defining an annular housing for said shorter arms and freely rotatably mounting them in said annular housing, and said annular housing having a corresponding cross section as said shorter arms.

4. Combination lock according to claim 1, in which the rotatable member comprises a central tubular member having one end closed and two sleeve-like parts, mounted on said tubular member concentric therewith, the two sleeve-like parts defining therebetween an annular recess in which said two actuating rings are freely rotatably mounted, said tubular mem- 

1. Combination lock including a rotatable member including a non-manually rotatable surface carrying at least one reference mark, at least two manually rotatable coaxial actuating rings each carrying a series of external reference marks, the actuating rings being placed about said rotatable member, the actuating rings having coaxial cylindrical inner walls each provided with a recess, an intermediary driving piece fixed for rotation with the rotatable member, an elastically radially outwardly urged active part of the driving piece bearing against said cylindrical inner walls when at least one of the recesses is out of alignment with the active part and engageable in the recesses to lock the rotatable member for rotation with at least one of the actuating rings when the rings are placed with a combination of their reference marks corresponding to alignment of all of the recesses with the active part, said driving piece comprising a bowed spring constrained to the form of a split ring, said rotatable member and actuating rings defining an annular groove defined between a peripheral wall of the rotatable member and the cylindrical inner walls of the actuating rings, said spring being disposed in said annular groove, a portion of the spring being fixed to the rotatable member, and a free end of the spring having an outwardly protruding cam forming said active part, a first one of said recesses having a profile which is adapted when the actuating rings are placed in said combination to engage with the cam and lock the corresponding first actuating ring for rotation with the rotatable member, a second one of the recesses having a profile which is adapted when the actuating rings are placed in said combination to move the cam out of engagement with the recesses when the corresponding second aCtuating ring is turned, and means for fixing said portion of the spring to the rotatable member in any one of a plurality of discrete positions each corresponding to a reference mark on the external surface of the rotatable member.
 2. Combination lock according to claim 1, in which the rotatable member comprises two sleeve-like parts having flat annular walls which come to face and axially define said annular groove when the two sleeve-like parts are placed together coaxially, said walls including a series of axial bores, and the spring having pins protruding from opposite faces thereof, the pins being engageable in selected ones of the bores to hold the two sleeve-like parts in a given angular relation to one another and to the spring.
 3. Combination lock according to claim 1 in which said actuating rings comprise two axially superimposed actuating rings, said actuating rings each having a substantially U-shaped section which when the rings are placed together form a substantially H-shaped section, the inner arms of the U-sections being shorter than the outer arms, said rotatable member defining an annular housing for said shorter arms and freely rotatably mounting them in said annular housing, and said annular housing having a corresponding cross section as said shorter arms.
 4. Combination lock according to claim 1, in which the rotatable member comprises a central tubular member having one end closed and two sleeve-like parts, mounted on said tubular member concentric therewith, the two sleeve-like parts defining therebetween an annular recess in which said two actuating rings are freely rotatably mounted, said tubular member having a flange at one end, one of said sleeve-like parts which includes said external surface bearing against said flange on one end of the tubular member, a locking piece removably secured on the other end of the tubular member, and the other of said sleeve-like parts bearing against said locking piece. 